Metabolic response to fasting in 6-week-old Steller sea lion pups (Eumetopias jubatus)

2000 ◽  
Vol 78 (5) ◽  
pp. 890-894 ◽  
Author(s):  
L D Rea ◽  
D AS Rosen ◽  
A W Trites
Keyword(s):  
Metabolic Response ◽  
Blood Chemistry ◽  
Steller Sea Lion ◽  
Metabolic Adaptation ◽  
Eumetopias Jubatus ◽  
Sea Lion ◽  
Sea Lions ◽  
Lipid Catabolism ◽  
In The Wild ◽  
Change In Mean

Four Steller sea lions (Eumetopias jubatus) aged 6 weeks were fasted for 2.5 d to determine how young pups mobilize energy reserves during short periods of fasting similar to those experienced in the wild. At 6 weeks of age, the pups lost 5.1 ± 0.3% of their body mass during 2 d of fasting, with an average daily mass loss of 0.7 ± 0.1 kg·d-1. Plasma blood urea nitrogen (BUN) concentration increased significantly from 3.0 ± 0.1 mM, after an overnight fast, to 4.8 ± 0.5 mM, after 2.5 d of fasting. It is apparent that BUN levels are quickly depressed, since after only an overnight fast, these pups showed BUN levels 2- to 4-fold lower than those measured after the same pups, when 9 months of age, had recently been fed fish. Plasma ketone body (β-HBA) concentrations of the 6-week-old pups increased significantly from 0.32 ± 0.08 to 0.42 ± 0.08 mM between 0.5 and 1.5 d of fasting. There was no significant change in mean plasma concentration beyond 1.5 d, owing to variable individual responses to extended fasting. Plasma β-HBA levels at 9 months of age ranged from 0.07 to 0.18 mM. Six-week-old Steller sea lion pups showed blood chemistry consistent with metabolic adaptation to fasting within 16 h but were unable to sustain a protein-sparing metabolism for a prolonged period. The pups appeared to revert to protein catabolism after only 2.5 d of fasting. This infers a decrease in lipid catabolism that might be due to the depletion of available lipid resources.

scholarly journals Overwintering Steller sea lion (Eumetopias jubatus) pup growth and behavior prior to weaning

2018 ◽  
Vol 96 (2) ◽  
pp. 97-106
Author(s):  
M.J. Rehberg ◽  
L.D. Rea ◽  
C.A. Eischens
Keyword(s):  
Nitrogen Isotope ◽  
Breeding Strategy ◽  
Individual Growth ◽  
Steller Sea Lion ◽  
Diving Behavior ◽  
Eumetopias Jubatus ◽  
Sea Lion ◽  
Sea Lions ◽  
Income Breeding ◽  
Lipid Mass

We measured individual growth, looked for evidence of weaning, and examined the interaction of these changes with diving behavior in young-of-year Steller sea lion (Eumetopias jubatus (Schreber, 1776)) pups in Alaska, USA, during their first winter. Steller sea lions employ an income breeding strategy, in which females provision their young over an individually variable period of months to years. Thus, we set out to identify whether these young sea lions showed evidence of weaning during the challenging winter months, describe the nature of their growth during this time, and examine their behaviors in light of these changes. Between 2005 and 2008, we captured 71 pups during early winter and recaptured 33 of these pups in early spring. Mark–resight and stable nitrogen isotope ratios in vibrissae indicated most pups remained nutritionally dependent on adult females throughout the winter. All pups increased both mass and lipid mass, with half of growth contributed by lipid mass. Changes in behavior were not correlated with growth excepting a weak but significant effect on rate of vertical travel. This study demonstrated that capture–recapture of Steller sea lion pups is possible, provided seasonal timing, locations, and age classes are carefully considered for their likelihood of capture success.

Examining the utility of fishery and survey data to detect prey removal effects on Steller sea lions (Eumetopias jubatus)

2014 ◽  
Vol 71 (8) ◽  
pp. 1229-1242 ◽  
Author(s):  
Paul B. Conn ◽  
Devin S. Johnson ◽  
Lowell W. Fritz ◽  
Brian S. Fadely
Keyword(s):  
Strong Relationship ◽  
Statistical Hypothesis ◽  
Steller Sea Lion ◽  
Eumetopias Jubatus ◽  
Vital Rates ◽  
Hypothesis Tests ◽  
Sea Lion ◽  
Fish Stocks ◽  
Sea Lions ◽  
The Relationship

One focus of mitigation for Steller sea lion (Eumetopias jubatus) declines in Alaska has been to restrict commercial fishery activity around sea lion rookeries and haul-outs. However, a variety of statistical hypothesis tests have failed to relate sea lion population metrics to fish and fishing variables, prompting speculation that regulations may be unwarranted. In this study, we use simulation to show that standard hypothesis tests often have overstated power to detect a relationship between Steller sea lion vital rates and fish or fishing variables. The power and utility of hypothesis tests largely depend on choosing appropriate dependent and independent variables. In particular, pup counts were the most effective for diagnosing fecundity effects, and successive ratios of adult counts were the most effective for diagnosing survival effects. Fish relative abundance was the most effective independent variable, with other choices (e.g., fishery catch) often resulting in misleading inferences. We argue that Bayes factors are best suited for characterizing the relationship between fish abundance and Steller sea lion vital rates and that existing evidence does not preclude a strong relationship between sea lion fecundity and the availability of commercially harvested fish stocks.

Milk fatty acid composition of perinatal and foraging Steller sea lions (Eumetopias jubatus): examination from pup stomachs

2018 ◽  
Vol 96 (2) ◽  
pp. 153-162 ◽  
Author(s):  
C.N. Miller ◽  
L.K. Polasek ◽  
A.C.M. Oliveira ◽  
C.J. Frost ◽  
J.M. Maniscalco
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Steller Sea Lion ◽  
Milk Fatty Acid ◽  
Eumetopias Jubatus ◽  
Steller Sea Lions ◽  
Sea Lion ◽  
Sea Lions

To investigate the milk fatty acid composition of female Steller sea lions (Eumetopias jubatus (Schreber, 1776)) between and within maternal states (i.e., perinatal or foraging), milk samples were collected in 2010 and 2011 via gastric intubation from Steller sea lion pups on a small rookery in the central Gulf of Alaska. Maternal states of lactating females were determined upon reuniting with their sampled pups via remotely operated video cameras on the rookery. Milk fatty acid composition between Steller sea lion maternal states was significantly different, and thus can be utilized to distinguish between perinatal and foraging Steller sea lions of the same geographic region in the absence of direct observation. However, milk fatty acid composition remained relatively constant within perinatal Steller sea lions, suggesting steady mobilization of fatty acids from blubber to milk, and within foraging Steller sea lions, implying females forage on similar prey species within several days after their perinatal period. Differences in milk fatty acid composition between maternal states, including differences in the relative percentages of polyunsaturated fatty acids, may have important implications for growth and development of offspring.

scholarly journals Steller Sea Lion (Eumetopias jubatus) Response to Non-lethal Hazing at Bonneville Dam

2021 ◽  
Vol 2 ◽  
Author(s):  
Kyle S. Tidwell ◽  
Brett A. Carrothers ◽  
Daniel T. Blumstein ◽  
Zachary A. Schakner
Keyword(s):  
Chinook Salmon ◽  
Steller Sea Lion ◽  
Eumetopias Jubatus ◽  
Steller Sea Lions ◽  
Sea Lion ◽  
Sea Lions ◽  
Physical Stimuli ◽  
Multiple Species ◽  
Fisheries Interactions

Protected Steller sea lions (Eumetopias jubatus) aggregate at Bonneville Dam on the Columbia River and prey upon multiple species of endangered salmon ascending the river. Hazing is a non-lethal activity designed to repel sea lions that includes aversive auditory and physical stimuli to deter animals from an area and has been employed with sea lion—fisheries interactions for more than 40 years but sea lion responses to hazing through time is not well-documented. We observed the behavior of Steller sea lions in periods with and without hazing during two spring Chinook salmon passage seasons to evaluate: (1) what effect hazing had on the number of animals present and their foraging behavior, and (2) whether they habituated to hazing. We found that hazing temporarily reduced the number of Steller sea lions, but only when actively hazed. During hazing, Steller sea lions were more likely to move away from hazers on the dam, decreased their foraging, and increased their time investigating the environment. However, these effects were temporary; their behavior returned to initial observation levels once hazing ceased. Furthermore, their responsiveness to hazing declined throughout the season, indicating habituation and raising concern for the application and long-term efficacy of hazing in managing predation on endangered salmon.

scholarly journals The oldest record of the Steller sea lion Eumetopias jubatus (Schreber, 1776) from the early Pleistocene of the North Pacific

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9709
Author(s):  
Nahoko Tsuzuku ◽  
Naoki Kohno
Keyword(s):  
North Pacific ◽  
Japan Sea ◽  
Early Pleistocene ◽  
Steller Sea Lion ◽  
Eumetopias Jubatus ◽  
Sea Lion ◽  
Sea Lions ◽  
The North ◽  
Fur Seals ◽  
The North Pacific

The extant genera of fur seals and sea lions of the family Otariidae (Carnivora: Pinnipedia) are thought to have emerged in the Pliocene or the early Pleistocene in the North Pacific. Among them, the Steller sea lion (Eumetopias jubatus) is the largest and distributed both in the western and eastern North Pacific. In contrast to the limited distribution of the current population around the Japanese Islands that is now only along the coast of Hokkaido, their fossil records have been known from the middle and late Pleistocene of Honshu Island. One such important fossil specimen has been recorded from the upper lower Pleistocene Omma Formation (ca. 1.36–0.83 Ma) in Kanazawa, Ishikawa Prefecture, Japan, which now bears the institutional number GKZ-N 00001. Because GKZ-N 00001 is the earliest fossil having been identified as a species of the sea lion genus Eumetopias, it is of importance to elucidate the evolutionary history of that genus. The morphometric comparisons were made among 51 mandibles of fur seals and sea lions with GKZ-N 00001. As results of bivariate analyses and PCA based on 39 measurements for external morphologies with internal structures by CT scan data, there is almost no difference between GKZ-N 00001 and extant male individuals of E. jubatus. In this regard, GKZ-N 00001 is identified specifically as the Steller sea lion E. jubatus. Consequently, it is recognized as the oldest Steller sea lion in the North Pacific. About 0.8 Ma, the distribution of the Steller sea lion had been already established at least in the Japan Sea side of the western North Pacific.

A late Pleistocene Steller sea lion (Eumetopias jubatus) from Courtenay, British Columbia: its death, associated biota, and paleoenvironment

2004 ◽  
Vol 41 (11) ◽  
pp. 1285-1297 ◽  
Author(s):  
C R Harington ◽  
R LM Ross ◽  
R W Mathewes ◽  
K M Stewart ◽  
O Beattie
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Steller Sea Lion ◽  
Eumetopias Jubatus ◽  
Sea Lion ◽  
Radiocarbon Dates ◽  
Sea Lions ◽  
Regional Sea Level

A partial juvenile Steller sea lion (Eumetopias jubatus) skeleton from nearshore marine sands at Courtenay, Vancouver Island, British Columbia has been radiocarbon dated to 12 570 ± 70 BP. This date is supported by both stratigraphic and regional sea-level emergence data and is similar to radiocarbon dates on a Steller sea lion humerus from Bowen Island, just north of Vancouver. The juvenile apparently died from a blow to the braincase, most likely caused by a Steller sea lion bull. The Courtenay specimen is significant since very few Pleistocene otariid fossils are complete enough to be assigned to modern taxa. Associated mollusk remains indicate that the marine paleoclimate of the fossil locality was considerably colder than now — close to that along the northern reaches of Cook Inlet and Prince William Sound, Alaska. Pollen and plant macrofossils collected from the Courtenay site clearly demonstrate the presence of lodgepole pine (Pinus contorta) forests nearby during this early late-glacial interval. Fish remains (mainly Pacific cod and walleye pollock, with some salmon) from this site probably reflect selection by adult sea lions at a rookery.

scholarly journals Dermatophytosis in a Steller Sea Lion (Eumetopias jubatus).

1994 ◽  
Vol 56 (3) ◽  
pp. 551-553 ◽  
Author(s):  
Eri TANAKA ◽  
Takahiro KIMURA ◽  
Sinpei WADA ◽  
Kisio HATAI ◽  
Seizaburou SONODA
Keyword(s):  
Steller Sea Lion ◽  
Eumetopias Jubatus ◽  
Sea Lion
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